1. Field of the Invention
The present invention relates to a multi-body problem processing apparatus for performing calculations for molecular dynamics, and more particularly, to a parameter storing method, a parameter storing device, a multi-body problem processing apparatus, and an address generator circuit which are suitable for performing the calculations.
2. Description of the Related Art
In multi-body problem processing apparatuses for performing calculations for molecular dynamics as disclosed in JP-A-6-223052 and JP-A-9-251449, a distance and an energy parameter must be taken into consideration in calculating nonassociative forces which act between multiple particles that exist within a three-dimensional space.
Conventionally, these parameters have been previously stored in a memory, such that parameters required for calculations are read to calculate the nonassociative force which acts between respective particles. Since these parameters differ depending on the type of particles, a number of parameters equal to the number of combinations of respective particles must be stored in the memory.
FIG. 1 is a block diagram illustrating the configuration of a main portion of a conventional multi-body problem processing apparatus. In the description of the prior art example, number P, which takes a value of 0 to N−1, is given in order to identify N types of particle species, and particle numbers in combination are designated by Pi and Pj.
In FIG. 1, address generator circuit 101 stores addresses corresponding to particle numbers Pi, Pj, and storage device 103 stores parameters corresponding to the addresses.
Upon application of particle numbers Pi, Pj, address generator circuit 101 generates address S101 corresponding to particle numbers Pi, Pj, and outputs address S101 to processing unit 2. Processing unit 102 reads parameters stored in storage device 103 corresponding to address S101, and performs processing to provide processing result S102.
FIG. 2 is a table showing how addresses are stored in address generator circuit 101.
There are N types in each of the two particles (labeled particle numbers Pi, Pj) intended for calculation, with zero inclusive, so that the final value of the address is represented by (N+1)2−1, and (N+1)2 different addresses are generated in total. Storage device 103 for storing parameters corresponding to each address stores (N+1)2 parameters corresponding to (N+1)2 addresses.
While parameters required to perform calculations for molecular dynamics have been previously stored in a memory and are read as required for calculations to calculate nonassociative forces which act between respective particles, these parameters differ depending on the type of the particles, so that a number of parameters equal to the number of combinations of the respective particles must be stored in memory, causing an increase in memory capacity by a significant factor in memory capacity (gate amount).